History is full of hoaxes, and that includes people who aren't really people. These "people" are handy, because they can be used as sources, they can be quoted, and they can be blamed. Because they don't exist, they won't mind!

Film fans and critics often rail against so-called “quote whores”—reviewers who are willing to write a positive notice for any movie as long as the studios wine and dine them enough—and David Manning of the Ridgefield Press was seemingly one of the worst. Around 2000, his glowing reviews frequently appeared on the posters for such universally loathed films as The Animal (“another winner!”) and Hollow Man (“stupendous!”). Manning would have been a running contender for America’s worst working film critic, save for one key detail: he didn’t exist. As it turned out, a marketing executive at Sony had invented Manning as a tool for building positive press for films released by the corporation’s subsidiary Columbia Pictures.

Read more about Manning and nine other nonexistent folks you may know at Top Tenz. Link

In my college days I'd put in a fictitious name and source in the bibliography. If a professor caught it I'd say it was done to protect my work against plagiarism. If memory serves me, the name I used was W.B. Tasker.